Taylor and Wells. — Preservation of Nets and Lines. 65 

 Table X. — Time required for application and drying of preservatives. 



Preservative 



Copper oleate 



Pine tar 50% in benzol 



Coal tar and pine tar, 50% benzol . 



Coal tar 50% benzol 



Quercitron : 

 Bull's method 1 f 



Dutch method/ \ 



Gilsonite 



Petroleum products, Nos. 1 and 2 . 



Copper paint I 



Copper paint II 



Number of applications 



and time required for 



each to dry 



One application. 

 One application. 

 One application. 

 One application. 



Three applications. 

 4 to 6 hours each. 

 One application. 

 One application. 

 One application. 

 One application. 



Total time required 

 for drying 



30 to 45 minutes. 

 10 to 12 hours. 

 20 to 24 hours. 

 24 hours. 



12 to 18 hours. 



24 hours. 

 36 to 48 hours. 

 36 hours. 

 48 hours. 



This record of the time required to apply the various preser- 

 vatives studied in this investigation shoves copper oleate to be 

 far in the lead. By any other method the lines or nets w^ould 

 require to be taken out of service at least a day for treatment, 

 not including the time necessary for drying the net before the 

 treatment is applied. 



In the case of copper oleate, lines or gear could be taken up, 

 dried and returned to use the same day, except in case of such 

 gear as pound nets, where the labor of taking up and setting 

 is excessive. In the case of gill nets, a very light application 

 can be applied frequently ; by so doing, little time is required, 

 and stififness and weight are kept at a minimum, but sufficient 

 copper can be kept in the line to effect excellent preservation. 



Copper paints, excellent preservatives though they are in 

 many other respects, are again at a disadvantage. 



The quercitron preservatives (and tanning methods in gen- 

 eral) are for practical purposes eliminated by the excessive time 

 and trouble required for their application. 



COLOR IMPARTED TO LINES BY THE PRESERVATIVES. 



All the preservatives studied change the color of the lines. 

 Just what the value of color in a line is, and what color and 

 shade would be preferable, we do not know. There is a large 

 literature on the subject of color vision in fishes, but results by 

 different observers are quite inconsistent. Still less do we know 

 of the reactions of fish to colors which they may distinguish. 

 However, since many people who are interested in net preserva- 



